[0001] The present invention relates to an antenna device that transmits and receives various
types of radio waves.
[0002] US patent application
US 2004/0041735 A1 discloses a vehicular radio wave receiver and information displaying apparatus with
radio wave receiver. Such receiver is provided with a circuit board and a dielectric
antenna. Such receiver shall comprise a high receiving performance sufficient for
use in a vehicle.
[0003] In the non-patent literature documents "practical Radio - Frequency handbook" [ISBN:
978-0-4506-8039-4], "single layer printed monopole antenna for dual ISM-Band operation"
[ISSN:0018-926X] and "small antenna design" [ISBN: 978-0-7560-7861-2] general background
knowledge with respect to the present invention is described.
[0004] An electronic key system installed in a vehicle uses an electronic key as a vehicle
key that transmits a unique key code through wireless communication to the vehicle.
One type of such an electronic key system is a wireless key system that requires the
operation of a button to transmit the key code. In such a wireless key system, when
a lock button of the electronic key is pushed, a lock request radio wave, which includes
a key code, is transmitted from the electronic key to the vehicle. Upon receipt of
the lock request radio wave, the vehicle locks unlocked doors if the key code in the
radio wave is correct. When an unlock button of the electronic key is pushed, an unlock
request radio wave, which includes the key code, is transmitted from the electronic
key to the vehicle. When the key code in the radio wave is correct, the vehicle unlocks
locked doors.
[0005] The electronic key system includes an antenna, which is installed in the vehicle
to receive various types of radio waves transmitted from the electronic key. One example
of such an antenna is an inverted L antenna. The inverted L antenna has the shape
of inverted letter L from the alphabet. Japanese Laid-Open Patent Publication No.
2003-8331 describes an example of an inverted L antenna. Fig. 1 is a schematic diagram showing
the structure of an inverted L antenna 110, which is described in the publication.
As shown in the drawing, the inverted L antenna 110 includes a generally U-shaped
antenna element 112, which has a vertical end extending orthogonally to a substrate
107 and a horizontally extending portion bent twice by 90 degrees. The antenna element
112 is arranged on a conductive surface, which is larger than the antenna element
112, and has a length set to be, for example, one fourth the wavelength. In this case,
the vehicle body or substrate that is larger than the wavelength may function as the
conductive surface. As the size of the conductive surface becomes greater than the
wavelength, the antenna properties are further stabilized.
[0006] A wire harness 130 is connected to the substrate 107, on which the antenna 110 is
mounted, to connect the antenna device 105 to another device. However, when coupling
the antenna device 105 to a vehicle body or the like, the layout situation (e.g.,
length and position) of the wire harness 130 differs in accordance with the application.
For example, the length of the antenna element 112 is determined by the wavelength.
However, when the antenna device 105 is required to be reduced in size, the substrate
107 must also be miniaturized. The antenna properties obtained with a large substrate
may not be obtained when the substrate 107 is miniaturized in such a manner. Further,
in the inverted L antenna 110, the antenna element 112 does not function as an antenna
by itself. Rather, the antenna element 112 cooperates with the substrate 107 to function
in the same manner as a dipole. Thus, the image produced on a ground plane of the
substrate 107 affects the antenna properties. Moreover, the conductive surface may
have an area that is not sufficiently larger than the wavelength. In such a case,
when the layout situation of the wire harness 130 differs depending on the application,
the wire harness 130, which is a conductor, functions as the ground plane and may
thereby vary the antenna directivity. This may destabilize the antenna properties.
Such a problem occurs in any antenna device that has a substrate connected to a conductor,
such as a wire harness connecting the antenna device to another device. That is, in
the antenna device of the prior art, a conductor 5 functioning as the ground plane,
which is affected by the layout situation of the conductor, varies and destabilizes
the antenna properties. Accordingly, it is desirable that the antenna properties be
stabilized without being affected by the state (position, length, and shape) of such
a conductor.
[0007] The present invention provides an antenna device that stabilizes the antenna properties
regardless of the state of a conductor connected to the antenna device.
[0008] The invention is defined according to claims 1 and 5. Specific embodiments are defined
in the subclaims which are referred back to claims 1 and 5, respectively.
[0009] Other embodiments and advantages of the present invention will become apparent from
the following description, taken in conjunction with the accompanying drawings, illustrating
by embodiments the principles of the invention.
[0010] The invention, together with objects and advantages thereof, may best be understood
by reference to the following description of the presently preferred embodiments together
with the accompanying drawings in which:
Fig. 1 is a schematic diagram showing an antenna device of the prior art;
Fig. 2 is a schematic diagram showing an electronic key system;
Fig. 3 is a schematic diagram showing an antenna device according to one embodiment
of 30 the present invention;
Fig. 4 is a waveform chart showing the antenna directivity of a horizontal polarized
wave on a horizontal plane;
Fig. 5 is a schematic diagram showing a modification of the antenna device of Fig.
3;
Fig. 6 is a schematic diagram showing a balun arranged in the antenna device of
Fig. 5;
Fig. 7 is a schematic diagram showing a modification of the antenna device of Fig.
3; and
Fig. 8 is a schematic diagram showing a modification of the antenna device of Fig.
3.
First Embodiment
[0011] One embodiment of an antenna device applied to a reception antenna 5 will now be
discussed with reference to Figs. 2 to 4. Referring to Fig. 2, a wireless key system,
which is one type of an electronic key system, is installed in a vehicle 1. The wireless
key system includes a wireless key 2, which transmits a unique key code through wireless
communication when a button is operated. The wireless key 2, which functions as an
electronic key, uses the radio frequency (RF) band as a communication frequency that
carries signals. The wireless key 2 includes a lock button 3, which is operated to
lock a door of the vehicle 1 (close a door lock), and an unlock button 4, which is
operated to unlock the door of the vehicle 1 (open the door lock). The reception antenna
5 is installed in the vehicle 1 and thereby functions as a vehicle antenna. The reception
antenna 5 corresponds to an antenna device.
[0012] In the wireless key system, when the lock button 3 of the wireless key 2 is pushed,
the wireless key 2 transmits a lock request radio wave 51 in the RF band as a signal
to the vehicle 1. The lock request radio wave 51 includes a key code of the wireless
key 2 and a lock request code for instructing the vehicle 1 to perform locking. When
the reception antenna 5 receives the lock request radio wave 51, the vehicle 1 performs
key verification with the key code included in the lock request radio wave 51. When
the key verification is successful, the door of the vehicle 1 is locked in accordance
with the lock request code. When the unlock button 4 of the wireless key 2 is pushed,
the wireless key 2 transmits an unlock request radio wave Su1 in the RF band as signal
to the vehicle 1. The unlock request radio wave 5u 1 includes the key code of the
wireless key 2 and an unlock request code for instructing the vehicle 1 to perform
unlocking. When the reception antenna 5 receives the unlock request radio wave Su1,
the vehicle 1 performs key verification with the key code included in the unlock request
radio wave Su1. When the key verification is successful, the door of the vehicle 1
is unlocked in accordance with the unlock request code.
[0013] As shown in Fig. 3, the reception antenna 5 includes a plate-shaped substrate 7.
Various antenna components of the reception antenna 5 are mounted on the substrate
7. A housing 6 accommodates the substrate 7. The housing 6 is coupled to a vehicle
body to install the 25 reception antenna 5 in the vehicle 1.
[0014] Pattern wiring 20 (circuit wiring), which serves as a circuit wiring, is formed on
the substrate 7. The pattern wiring 20 is separated into a first pattern portion 21
(first wiring portion) and a second pattern portion 22 (second wiring portion) on
the substrate 7. As viewed in Fig. 3, in this embodiment, the first pattern portion
21 is located at the upper left part of the substrate 7, and the second pattern portion
22 is located at the lower part of the substrate 7. Preferably, the first pattern
portion 21 is sufficiently smaller than the entire area of the substrate 7. In this
embodiment, the first pattern portion 21 is approximately one-sixth the entire area
of the substrate 7. The first and second pattern portions 21 and 22 are partially
connected when the same potential, such as ground (GND), is necessary. A wireless
circuit 8 and an electronic circuit 9 are arranged on the pattern wiring 20. The wireless
circuit 8 manages the reception operation of the reception antenna 5. The electronic
circuit 9 controls the reception operation. The wireless circuit 8 is arranged on
the first pattern portion 21, and the electronic circuit 9 is arranged on the second
pattern portion 22. Thus, the wireless circuit 8 and the electronic circuit 9 are
arranged in positional isolation from each other on the substrate 7.
[0015] A pattern stub 23 (shaded part in Fig. 3), which has a pattern length allowing for
resonance to occur at one fourth of a wavelength of a reception signal (communication
signal), is formed in the first pattern portion 21, which includes the wireless circuit
8. In the embodiment, the pattern stub 23 is laid out along two sides (upper edge
and right edge in Fig. 3) of the substrate 7. By using the edges of the substrate
7, the pattern stub 23 is efficiently formed within the limited space of the substrate
7. One fourth of a wavelength refers to one fourth of a single wavelength of a reception
signal. A pattern length that causes resonance at one fourth of the wavelength includes
a pattern length that is equal to one fourth of the wavelength as shown in Fig. 3.
However, the pattern stub 23 may be formed to be longer than one fourth of the wavelength.
In 5 this case, the pattern length may be varied as long as it is obtained by adding
the product of one half of the wavelength and a natural number to one fourth of the
wavelength (i.e., λ/4+(n • λ/2), where A represents a wavelength and n represents
a natural number). Further, when forming the pattern wiring 20 on the substrate 7,
the pattern length of the pattern stub 23 may be shorter than one fourth of the wavelength
due to the permittivity of a dielectric on the substrate 7. Accordingly, a pattern
length that causes resonance at one fourth of the wavelength refers to a pattern length
that causes the pattern stub to resonate at one fourth of the wavelength. This includes
a pattern that is slightly shorter than one fourth of the wavelength.
[0016] An inverted L antenna 10 is mounted on the substrate 7. The inverted L antenna 10
includes an antenna element 12, which serves as an antenna line. The antenna element
12, which is a component formed from, for example, metal such as aluminum, is arranged
generally parallel to the substrate 7. The inverted L antenna 10 does not function
as an antenna just with the antenna element 12. The antenna element 12 affects and
cooperates with the substrate 7 to function in the same manner as a dipole. The antenna
element 12 includes an end portion, which extends in the vertical direction from a
power supply point 11 (power supply terminal) on the substrate 7 and is bent 90 degrees.
From this bent end portion, the antenna element 12 is bent twice by 90 degrees and
extends in the horizontal direction. Thus, the antenna element 12 is generally U-shaped
and lies along a plane parallel to the substrate 7. The antenna element 12 has a length
set to be equal to one fourth of the wavelength. The length of the antenna element
12 does not have to be equal to the length of the pattern stub 23. In an embodiment
the antenna element 12 may have a length that is equal to one fourth of the wavelength,
and the pattern stub 23 may have a length that is equal to three fourths of the wavelength.
The power supply point 11 is set at one position on the pattern wiring 20 (first pattern
portion 21) of the substrate. When receiving a radio wave, the antenna provides the
wireless circuit 8 with current that is in accordance with the received radio wave
(progressive wave).
[0017] A wire harness 30, which serves as a conductor, is connected to the substrate 7.
The wire harness 30 connects the reception antenna 5 to another device or power supply
in the vehicle 1. When coupling the reception antenna 5 to the vehicle body, the layout
situation and form of the wire harness 30 arranged on the vehicle body may differ
for each application. In the reception antenna of the prior art, when the layout situation
of a wire harness changes, the wire harness, which is a conductor, functions as a
ground plane for the antenna element. This may vary the antenna properties and thereby
destabilize the antenna properties.
[0018] To solve this problem, in the reception antenna 5 of the present embodiment, the
pattern stub 23, which has a pattern length that causes resonance at one fourth of
the wavelength, is formed in the first pattern portion 21, which includes the wireless
circuit 8. Accordingly, the antenna element 12 of the antenna 10 resonates with the
pattern stub 23 and stabilizes the antenna properties. In this case, the shape of
the pattern stub 23 formed on the substrate 7 remains the same. Thus, the antenna
properties do not vary. Accordingly, the antenna properties are stabilized.
[0019] The antenna directivity of the reception antenna 5 is an index that indicates the
reception sensitivity of the reception antenna 5 with respect to various radio waves
transmitted from the wireless key 2. More specifically, the antenna directivity is
indicated by a value representing the reception sensitivity with respect to the direction
of the antenna element 12 (inverted L antenna 10). A higher antenna directivity value
indicates a higher reception sensitivity. The ideal antenna directivity is round (circular)
so that whichever direction the wireless key 2 transmits a radio wave to the antenna
10 (vehicle 1), the transmitted radio wave reaches the antenna 10 from about the same
distance. Thus, in this type of reception antenna 5, there is a demand that the antenna
directivity be as round as possible. A rounder antenna directivity improves the antenna
properties.
[0020] When discussing the antenna directivity, the antenna directivity roundness on a plane
extending in the horizontal direction (horizontal plane), which serves as a reception
plane of the antenna 10 in the vehicle 1, must be taken into consideration. The wireless
key 2 is used to transmit radio waves in the horizontal direction near the vehicle
1 (in a direction extending along the ground surface). Thus, the radio wave transmission
direction of the wireless key 2 extends along a horizontal plane.
[0021] Fig. 4 is a chart showing the antenna directivity of the reception antenna 5 in the
presently described embodiment. In the chart of Fig. 4, the marks in the circumferential
direction represent angles (0 degrees to 360 degrees) and the marks in the radial
direction represent reception sensitivities. In the chart, the single-dashed line
shows a waveform Ma indicating the antenna directivity for the reception antenna of
the prior art and the reception antenna 5 of the presently described embodiment when
the wire harness 30 is arranged at the desired position, that is, the originally designed
position. The broken line shows a waveform Mb indicating the antenna directivity for
the reception antenna of the prior art when the wire harness is not arranged at the
desired position, that is, when the wire harness is displaced within a tolerance.
The solid line shows a waveform Mc indicating the antenna directivity for the reception
antenna 5 of the presently described embodiment when the wire harness 30 is not arranged
at the desired position, that is, when the wire harness 30 is displaced within a tolerance.
[0022] The waveform Mb, which is for the reception antenna of the prior art when the wire
harness is not arranged at the desired position, is more greatly deviated from a circle
than the waveform Ma, which is for the reception antenna of the prior art and the
reception antenna 5 of the presently described embodiment when the wire harness 30
is arranged at the desired position. However, the waveform Mc, which is for the reception
antenna 5 of the presently described embodiment when the wire harness 30 is not arranged
at the desired position, varies subtly from the waveform Ma, which is for the reception
antenna 5 of the presently described embodiment when the wire harness 30 is arranged
at the desired 40 position. This shows that the layout situation of the wire harness
30 does not affect the directivity of the reception antenna 5.
[0023] The antenna device of the first embodiment has the advantages described below.
- (1) The wireless circuit 8 and the electronic circuit 9 are arranged in positional isolation
from each other on the substrate 7. Further, the pattern wiring 20 arranged on a semiconductor
portion of the substrate 7 is divided into the first and second pattern portions 21
and 22. This prevents the second pattern portion 22, which includes the electronic
circuit 9, from functioning as a ground plane and maintains the desirable antenna
properties. This structure is particularly desirable since the antenna element 12
does not function as an antenna by itself in the inverted L antenna 10 and cooperates
with the substrate 7 to function in the same manner as a dipole. Further, the first
pattern portion 21, which includes the wireless circuit 8, includes the pattern stub
23, which has a pattern length that causes resonance at one fourth of the wavelength.
In this structure, the antenna element 12 resonates with the pattern stub 23 and stabilizes
the antenna properties. Since the shape of the pattern stub 23 formed on the substrate
7 remains the same, the antenna directivity does not vary even when the layout situation
or shape of the wire harness 30 connected to the substrate differs between applications.
In other words, resonance of the antenna element 12 with the pattern stub 23 occurs
regardless of the layout situation (position or shape) of the wire harness 30. This
prevents a conductor connected to the reception antenna 5, such as the wire harness
30, from affecting the antenna properties and thereby stabilizes the antenna properties.
- (2) The first pattern portion 21, which includes the wireless circuit 8, is formed
to be sufficiently smaller in size than the entire substrate 7. In other words, the
ratio of the area for the first pattern portion 21 occupying the substrate 7 is small.
This prevents the second pattern portion 22 from functioning as the ground plane and
maintains the desirable antenna properties.
Second Embodiment
[0024] A second embodiment of an antenna device applied to a reception antenna 5 will now
be discussed with reference to Figs. 5 and 6. The reception antenna 5 of the second
embodiment differs from the first embodiment in that it includes a balun 25, which
is a balanced to unbalanced converter. The difference from the first embodiment will
now be discussed. The antenna device of the second embodiment has a structure that
is similar to that of the antenna device of the first embodiment shown in Fig. 3.
[0025] Referring to Fig. 5, the balun is arranged on the first pattern portion 21. The balun
25 is arranged between the antenna element 12 and the wireless circuit 8 and between
the pattern stub 23 and the wireless circuit 8 so that unbalanced current does not
flow to the antenna element 12 and the pattern stub 23.
[0026] In an embodiment, as shown in Fig. 6, the balun 25 is connected between the wireless
circuit 8 and the antenna element 12 and includes a transformer connected between
the wireless circuit 8 and the pattern stub 23. The pattern stub 23 is connected to
ground. 40 In addition to advantages (1) and (2) of the first embodiment, the second
embodiment has the advantage described below.
(3) The balun 25 resonates in correspondence with resonance of the antenna element
12. The balun 25 prevents unbalanced current from flowing to the antenna element 12
and the pattern stub 23 and allows balanced current to flow to the wireless circuit
8. This prevents the antenna properties from being destabilized by unbalanced currents.
Third Embodiment
[0027] A third embodiment of an antenna device applied to a reception antenna 5 will now
be discussed with reference to Fig. 7. The reception antenna 5 of the third embodiment
differs from the first embodiment in that a pattern stub 27 is combined with a resonator.
The difference from the first embodiment will now be discussed. The antenna device
of the third embodiment has a structure that is similar to that of the antenna device
of the first embodiment shown in Fig. 3.
[0028] Referring to Fig. 7, the pattern stub 27 has a length that is set to be approximately
one eighth of the wavelength, which is shorter than the one fourth of the wavelength
in the first embodiment. The second pattern portion 22 has an area that is wider than
that of the second pattern portion 22 in the first embodiment (refer to Fig. 5). More
specifically, in the antenna structure of the third embodiment, the second pattern
portion 22 is enlarged, and the pattern stub 27 cannot have a length that is one fourth
of the wavelength. The first pattern portion 21 and the pattern stub 27 are isolated
from each other. A lumped constant circuit 26, which functions as the resonator, is
arranged between the first pattern portion 21 and the pattern stub 27. In the presently
described embodiment, the lumped constant circuit 26 is an inductor (L). Further,
the lumped constant circuit 26 functions as part of the pattern stub 27 and resonates
the antenna element 12 and the pattern stub 27 even though the pattern stub 27 is
shorter than one fourth of a wavelength.
[0029] In addition to advantages (1) and (2) of the first embodiment, the antenna device
of the third embodiment has the advantage described below.
(4) An inductor (lumped constant circuit 26) is used as a resonator in lieu of part
of the pattern stub 27. Even when the pattern stub 27 on the substrate 7 does not
have a pattern length that causes resonance at one fourth of the wavelength, the antenna
element 12 and the pattern stub 27 are resonated at the same frequency. Thus, the
pattern stub 27 that causes resonance at one fourth of a wavelength may have a shorter
length (in an embodiment, a length that is shorter than one fourth of the wavelength).
[0030] It should be apparent to those skilled in the art that the present invention may
be embodied in many other specific forms without departing from the scope of the invention.
Particularly, it should be understood that the present invention may be embodied in
the following forms.
[0031] In the second embodiment, the balun 25 does not need to be of a transformer type
and may have a structure of another type.
[0032] In the third embodiment, the pattern length of the pattern stub 27 is not limited
to one eighth of a wavelength and may be varied in accordance with the pattern length
of the pattern stub 27.
[0033] In the third embodiment, the lumped constant circuit 26 is used in lieu of part of
the pattern stub 27. However, the lumped constant circuit 26 may be used in lieu of
the entire pattern stub 27. Further, instead of or in addition to arranging the lumped
constant circuit 26 (resonator) at one end of the pattern stub 27 as shown in Fig.
7, the lumped constant circuit 26 may be arranged in a middle part of the pattern
stub 27. In an embodiment, a plurality of lumped constant circuits 26 (resonators)
may be arranged connecting two or more pattern stubs.
[0034] In the third embodiment, the lumped constant circuit 26, which serves as a resonator,
may be a capacitor (C) instead of an inductor (L). Otherwise, the lumped constant
circuit 26 may be an LC circuit, which includes an inductor and a capacitor.
[0035] In the above-described embodiments, the quantity of the pattern stub 23 is not limited
to one. A plurality of pattern stubs may be arranged in the first pattern portion
21. Fig. 8 shows a modification of the first embodiment (Fig. 3). In the example shown
in Fig. 8, the first pattern portion 21 is located in part of the left side of the
substrate 7, and the second pattern portion 22 is located at the lower side of the
substrate 7. A plurality of stubs, particularly, a first pattern stub 28 and a second
pattern stub 29, are connected to the first pattern portion 21. Each of the pattern
stubs 28 and 29 has a pattern length that allows for resonance to occur at one fourth
of the wavelength. Here, each of the first and second pattern stubs 28 and 29 has
a length that is one fourth of the wavelength. In this structure, at least one of
the pattern stubs 28 and 29, which causes resonance at one fourth of the wavelength,
functions as a ground plane and thereby prevents a wire harness or the like from functioning
as a ground plane. Thus, the antenna properties do not vary even when the layout situation
of the conductor connected to the substrate changes. This obtains stable antenna properties.
[0036] In the above-described embodiments, the first pattern portion 21 including the wireless
circuit 8 on the substrate does not have to be formed to be sufficiently small relative
to the entire area of the substrate 7.
[0037] In the above-described embodiments, the antenna 10 is not limited to an inverted
L antenna and may be a monopole antenna. Alternatively, the antenna 10 may be a T
antenna or any antenna of which the antenna properties are affected by an image produced
in a ground plane of the substrate 7.
[0038] In the above-described embodiments, the antenna device is not limited to the reception
antenna 5 and may be, particularly, a transmission antenna. Alternatively, the antenna
device may be a transmission-reception antenna that is used for both signal transmission
and signal reception. In such a case, one fourth of the wavelength refers to one fourth
of a wavelength of a transmission-reception signal, and one eighth of a wavelength
refers to one eighth of a wavelength of the transmission-reception signal.
[0039] The electronic key system is not necessarily limited to a wireless key system and
may be a key-operation-free system that automatically transmits a key code from an
electronic key (vehicle key). In such a key-operation-free system, the vehicle continuously
or intermittently transmits a key code reply request. In response to the request,
the electronic key returns a key code to the vehicle 1.
[0040] In the above-described embodiments, the antenna device (reception antenna 5 or the
like) does not have to be installed in the vehicle 1 and may be used in any device
or apparatus that performs wireless communication.
[0041] The present examples and embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details given herein, but
may be modified within the scope of the appended claims.
1. Antenna device (5), comprising:
a rectangular plate-shaped substrate (7) comprising a pattern wiring with a first
pattern portion (21) and a second pattern portion (22) which are arranged in positional
isolation from each other on the substrate (7), wherein on the first pattern portion
(21) a wireless circuit (8) and on the second pattern portion (22) an electronic circuit
(9) are arranged;
an antenna element (12) for transmiting or receiving a communication signal, wherein
the antenna element (12) includes an end portion which extends in the vertical direction
with regard to the extension of the substrate from a power supply point (11) on the
substrate (7) in the first pattern portion (21) and which is bent by 90 degrees, wherein
from this bent end portion the antenna element (12) is bent twice by 90 degrees and
extends parallel to the extension of the substrate (7) with a first, a second and
a third straight portion such that in this extension the first, the second and the
third straight portion form a U-shaped portion of the antenna element (12), wherein
the first straight portion and the second straight portion are arranged along a first
and a second side edge which form a first corner of the substrate (7);
the wireless circuit (8) which is connected to the antenna element (12) and which
is designed for managing the reception operation of the antenna device (5);
the electronic circuit (9) that differs from the wireless circuit (8) and which is
designed for control of the reception operation;
a wire harness (30) which serves as a conductor and is connected to the second pattern
portion (22) at the second side edge of the substrate (7) to connect the antenna device
(5) to a power supply; and
a pattern stub (23) which is formed in the first pattern portion (21) and which completes
a strip-shaped area of the first pattern portion (21) so that the second pattern portion
(22) is prevented from functioning as a ground plane and the antenna element (12)
in cooperation with the stub functions as a dipole, the stub (23, 27, 28, 29) having
a pattern length that causes resonance at one fourth of a single wavelength of the
communication signal or that causes resonance at (N4 +(n • N2)) of a single wavelength of the communication signal where λ represents
a wave length and n represents a natural number,
wherein the pattern stub (23) extends from an area, in which the wireless circuit
(8) is positioned, along a third side edge of the substrate (7) which lies opposite
to the second side edge of the substrate (7) at which the wire harness (30) is connected
to the substrate (7), extends along this edge and continues to extend along a fourth
side edge of the substrate (7) which extends parallel to the direction of the first
straight portion of the shaped portion of the antenna element (12) which first straight
portion starts from the end portion of the antenna element (12) which extends in the
vertical direction, wherein the third and fourth side edges along which the pattern
stub (23) is arranged form a second corner of the substrate (7), wherein the first
and the second corner lie diagonally opposite each other.
2. Antenna device (5) according to claim 1, wherein the first pattern portion (21) is
formed to be in size one sixth of the entire area of the substrate (7).
3. Antenna device (5) according to any of the preceding claims, further comprising:
a balanced to unbalanced converter (25) arranged between the antenna element (12)
and the wireless circuit (8) and between the stub (23) and the wireless circuit (8)
so that unbalanced current does not flow to the antenna element (12) and the pattern
stub (23).
4. Antenna device (5) according to claims 1 or 2, wherein the balanced to unbalanced
converter (25) includes a transformer, the transformer being connected to the antenna
element (12), the stub (23), and the wireless circuit (8) wherein the pattern stub
(23) is connected to ground, so that unbalanced current does not flow to the antenna
element (12) and the pattern stub (23).
5. Antenna device (5), comprising:
a rectangular plate-shaped substrate (7) comprising a pattern wiring with a first
pattern portion (21) and a second pattern portion (22) which are arranged in positional
isolation from each other on the substrate (7), wherein on the first pattern portion
(21) a wireless circuit (8) and on the second pattern portion (22) an electronic circuit
(9) are arranged;
an antenna element (12) for transmitting or receiving a communication signal, wherein
the antenna element (12) includes an end portion which extends in the vertical direction
with regard to the extension of the substrate from a power supply point (11) on the
substrate (7) in the first pattern portion (21) and which is bent by 90 degrees, wherein
from this bent end portion the antenna element (12) is bent twice by 90 degrees and
extends parallel to the extension of the substrate (7) with a first, a second and
a third straight portion such that in this extension the first, the second and the
third straight portion form a U-shaped portion of the antenna element (12), wherein
which first straight portion starts from the end portion of the antenna element (12)
which extends in the vertical direction, wherein the first straight portion and the
second straight portion are arranged along two side edges which form a first corner
of the substrate (7);
the wireless circuit (8) which is connected to the antenna element (12) and which
is designed for managing the reception operation of the antenna device (5);
the electronic circuit (9) that differs from the wireless circuit (8) and which is
designed for control of reception operation;
a wire harness (30) which serves as a conductor and is connected to the second pattern
portion of the second side edge of the substrate (7) to connect the antenna device
(5) to a power supply; and
a pattern stub (27) which is formed in the first pattern portion (21) and which completes
a strip-shaped area of the first pattern portion (21) so that the second pattern portion
(22) is prevented from functioning as a ground plane and the antenna element (12)
in cooperation with the stub functions as a dipole,
wherein the stub (27) extends from an area in which the wireless circuit (8) is positioned
along an edge of the substrate (7) which lies opposite to an edge of the substrate
(7) at which the wire harness (30) is connected to the substrate (7) and extends along
this edge to a second corner, wherein the first and the second corner lie diagonally
opposite each other,
wherein a lumped constant circuit (26) is arranged between the first pattern portion
(21) and the stub (27) so that the lumped constant circuit (26) functions as part
of the pattern stub (27) and resonates the antenna element (12) and the pattern stub
(27) even though the pattern stub (27) is shorter than one fourth of a wavelength
of the communication signal.
6. Antenna device (5) according to claim 5, wherein the lumped constant circuit (26)
is an inductor.
1. Antennenvorrichtung (5), die Folgendes aufweist:
ein rechteckförmiges, plattenförmiges Substrat (7), das eine Leiterverdrahtung mit
einem ersten Leiterplattenabschnitt (21) und einem zweiten Leiterplattenabschnitt
(22) aufweist, die in positioneller Isolierung voneinander auf dem Substrat (7) angeordnet
sind, wobei auf dem ersten Leiterplattenabschnitt (21) ein drahtloser Schaltkreis
(8) und auf dem zweiten Leiterplattenabschnitt (22) ein elektronischer Schaltkreis
(9) angeordnet ist;
ein Antennenelement (12) zum Senden oder Empfangen eines Kommunikationssignals, wobei
das Antennenelement (12) einen Endabschnitt aufweist, der sich in der vertikalen Richtung
in Bezug auf die Erstreckung des Substrats von einer Stromversorgungsstelle (11) auf
dem Substrat (7) in dem ersten Leiterplattenabschnitt (21) erstreckt und der um 90
Grad gebogen ist, wobei das Antennenelement (12) von diesem gebogenen Endabschnitt
zweimal um 90 Grad gebogen ist und sich parallel zu der Erstreckung des Substrats
(7) mit einem ersten, einem zweiten und einem dritten geraden Abschnitt erstreckt,
so dass der erste, der zweite und der dritte gerade Abschnitt in dieser Erstreckung
einen U-förmigen Abschnitt des Antennenelements (12) bilden, wobei der erste gerade
Abschnitt und der zweite gerade Abschnitt entlang einer ersten und einer zweiten Seitenkante
angeordnet sind, die eine erste Ecke des Substrats (7) bilden;
der drahtlose Schaltkreis (8), der mit dem Antennenelement (12) verbunden ist und
der zur Durchführung des Empfangsbetriebs der Antennenvorrichtung (5) ausgeführt ist;
der elektronische Schaltkreis (9), der sich von dem drahtlosen Schaltkreis (8) unterscheidet
und der zur Steuerung des Empfangsbetriebs ausgeführt ist;
einen Kabelstrang (30), der als ein Leiter dient und mit dem zweiten Leiterplattenabschnitt
(22) an der zweiten Seitenkante des Substrats (7) verbunden ist, um die Antennenvorrichtung
(5) mit einer Stromversorgung zu verbinden; und
einen Leiterplatten-Stichleitung (23), der als der erste Leiterplattenabschnitt (21)
ausgebildet ist und der einen streifenförmigen Bereich des ersten Leiterplattenabschnitts
(21) abschließt, so dass der zweite Leiterplattenabschnitt (22) daran gehindert wird,
als Massepotential zu fungieren, und das Antennenelement (12) in Zusammenwirkung mit
der Stichleitung als ein Dipol fungiert, wobei die Stichleitung (23, 27, 28, 29) eine
Leiterlänge hat, die eine Resonanz mit einem Viertel einer einzelnen Wellenlänge des
Kommunikationssignals bewirkt oder die eine Resonanz mit (λ/4 + (n • λ/2)) einer einzigen
Wellenlänge des Kommunikationssignals bewirkt, wobei λ für eine Wellenlänge steht
und n für eine natürliche Zahl steht,
wobei sich die Leiterplatten-Stichleitung (23) von einem Bereich, in dem der drahtlose
Schaltkreis (8) positioniert ist, entlang einer dritten Seitenkante des Substrats
(7) erstreckt, die entgegen gesetzt zu der zweiten Seitenkante des Substrats (7) liegt,
an der der Kabelstrang (30) mit dem Substrat (7) verbunden ist, sich entlang dieser
Kante erstreckt und sich weiterhin entlang einer vierten Seitenkante des Substrats
(7) erstreckt, die sich parallel zu der Richtung des ersten geraden Abschnitts des
geformten Abschnitts des Antennenelements (12) erstreckt, wobei dieser erste gerade
Abschnitt bei dem Endabschnitt des Antennenelements (12) beginnt, der sich in der
vertikalen Richtung erstreckt, wobei die dritte und die vierte Seitenkante, entlang
derer die Leiterplatten-Stichleitung (23) angeordnet ist, eine zweite Ecke des Substrats
(7) bilden, wobei die erste und die zweite Ecke zueinander diagonal entgegen gesetzt
liegen.
2. Antennenvorrichtung (5) nach Anspruch 1, wobei der erste Leiterplattenabschnitt (21)
derart ausgebildet ist, dass dieser eine Größe von einem Sechstel des gesamten Bereichs
des Substrats (7) hat.
3. Antennenvorrichtung (5) nach einem der vorhergehenden Ansprüche, die weiterhin Folgendes
umfasst: ein Balun (25), das zwischen dem Antennenelement (12) und der drahtlosen
Schaltung (8) und zwischen der Stichleitung (23) und der drahtlosen Schaltung (8)
angeordnet ist, so dass unkompensierter Strom nicht zu dem Antennenelement (12) und
der Leiterstichleitung (23) fließt.
4. Antennenvorrichtung (5) nach Anspruch 1 oder 2, wobei das Balun (25) einen Transformator
aufweist, wobei der Transformator mit dem Antennenelement (12), der Stichleitung (23)
und der drahtlosen Schaltung (8) verbunden ist, wobei die Leiterplatten-Stichleitung
(23) mit Masse verbunden ist, so dass unsymmetrischer Strom nicht zu dem Antennenelement
(12) und der Leiterplatten-Stichleitung (23) fließt.
5. Antennenvorrichtung (5), die Folgendes umfasst:
ein rechteckförmiges, plattenförmiges Substrat (7), das eine Leiterverdrahtung mit
einem ersten Leiterabschnitt (21) und einem zweiten Leiterplattenabschnitt (22) aufweist,
die in positioneller Isolierung voneinander auf dem Substrat (7) angeordnet sind,
wobei auf dem ersten Leiterplattenabschnitt (21) ein drahtloser Schaltkreis (8) und
auf dem zweiten Leiterplattenabschnitt (22) ein elektronischer Schaltkreis (9) angeordnet
ist;
ein Antennenelement (12) zum Senden oder Empfangen eines Kommunikationssignals, wobei
das Antennenelement (12) einen Endabschnitt aufweist, der sich in der vertikalen Richtung
in Bezug auf die Erstreckung des Substrats von einer Stromversorgungsstelle (11) auf
dem Substrat (7) in dem ersten Leiterplattenabschnitt (21) erstreckt und der um 90
Grad gebogen ist, wobei das Antennenelement (12) von diesem gebogenen Endabschnitt
zweimal um 90 Grad gebogen ist und sich parallel zu der Erstreckung des Substrats
(7) mit einem ersten, einem zweiten und einem dritten geraden Abschnitt erstreckt,
so dass der erste, der zweite und der dritte gerade Abschnitt in dieser Erstreckung
einen U-förmigen Abschnitt des Antennenelements (12) bilden, wobei dieser erste gerade
Abschnitt bei dem Endabschnitt des Antennenelements (12) beginnt, der sich in der
vertikalen Richtung erstreckt, wobei der erste gerade Abschnitt und der zweite gerade
Abschnitt entlang zwei Seitenkanten angeordnet sind, die eine erste Ecke des Substrats
(7) bilden;
der drahtlose Schaltkreis (8), der mit dem Antennenelement (12) verbunden ist und
der zur Durchführung des Empfangsbetriebs der Antennenvorrichtung (5) ausgeführt ist;
der elektronische Schaltkreis (9), der sich von dem drahtlosen Schaltkreis (8) unterscheidet
und der zur Steuerung des Empfangsbetriebs ausgeführt ist;
einen Kabelstrang (30), der als ein Leiter dient und mit dem zweiten Leiterplattenabschnitt
der zweiten Seitenkante des Substrats (7) verbunden ist, um die Antennenvorrichtung
(5) mit einer Stromversorgung zu verbinden; und
eine Leiterplatten-Stichleitung (23), der als dem erste Leiterplattenabschnitt (21)
ausgebildet ist und der einen streifenförmigen Bereich des ersten Leiterplattenabschnitts
(21) abschließt, so dass der zweite Leiterplattenabschnitt (22) daran gehindert wird,
als Massepotential zu fungieren, und das Antennenelement (12) in Zusammenwirkung mit
der Stichleitung als ein Dipol fungiert,
wobei sich die Stichleitung (27) von einem Bereich, in dem der drahtlose Schaltkreis
(8) positioniert ist, entlang einer Kante des Substrats (7) erstreckt, die entgegen
gesetzt zu einer Kante des Substrats (7) liegt, an der der Kabelstrang (30) mit dem
Substrat (7) verbunden ist, und sich entlang dieser Kante zu einer zweiten Ecke erstreckt,
wobei die erste und die zweite Ecke zueinander diagonal entgegen gesetzt liegen,
wobei ein reduzierter Konstantschaltkreis (26) zwischen dem ersten Leiterplattenabschnitt
(21) und der Stichleitung (27) angeordnet ist, so dass der reduzierte Konstantschaltkreis
(26) als Teil der Musterstichleitung (27) fungiert und das Antennenelement (12) und
die Musterstichleitung (27) resonieren lässt, obwohl die Musterstichleitung (27) kürzer
als ein Viertel einer Wellenlänge des Kommunikationssignals ist.
6. Antennenvorrichtung (5) nach Anspruch 5, wobei der reduzierte Konstantschaltkreis
(26) ein Induktor ist.
1. Dispositif d'antenne (5), comprenant :
un substrat en forme de plaque rectangulaire (7) comprenant un câblage de motif avec
une première portion de motif (21) et une deuxième portion de motif (22) qui sont
agencées en isolation positionnelle l'une de l'autre sur le substrat (7), dans lequel
sur la première portion de motif (21) un circuit sans fil (8) et sur la deuxième portion
de motif (22) un circuit électronique (9) sont agencés ;
un élément d'antenne (12) pour transmettre ou recevoir un signal de communication,
dans lequel l'élément d'antenne (12) comprend une portion d'extrémité qui s'étend
dans la direction verticale par rapport à l'extension du substrat à partir d'un point
d'alimentation électrique (11) sur le substrat (7) dans la première portion de motif
(21) et qui est incurvée de 90 degrés, dans lequel à partir de cette portion d'extrémité
incurvée l'élément d'antenne (12) est incurvé deux fois de 90 degrés et s'étend parallèlement
à l'extension du substrat (7) avec une première portion droite, une deuxième portion
droite et une troisième portion droite de sorte que dans cette extension la première
portion droite, la deuxième portion droite et la troisième portion droite constituent
une portion en forme de U de l'élément d'antenne (12), dans lequel la première portion
droite et la deuxième portion droite sont agencées le long d'un premier bord de côté
et d'un deuxième bord de côté constituant un premier coin du substrat (7) ;
le circuit sans fil (8) qui est relié à l'élément d'antenne (12) et qui est conçu
pour gérer l'opération de réception du dispositif d'antenne (5) ;
le circuit électronique (9) qui diffère du circuit sans fil (8) et qui est conçu pour
commander l'opération de réception ;
un faisceau de câblage (30) qui sert de conducteur et qui est relié à la deuxième
portion de motif (22) au deuxième bord de côté du substrat (7) pour relier le dispositif
d'antenne (5) à une alimentation électrique ; et
un bras de réactance de motif (23) qui est formé dans la première portion de motif
(21) et qui complète une zone en forme de bande de la première portion de motif (21)
de sorte que la deuxième portion de motif (22) soit empêchée de fonctionner en tant
que potentiel de terre et l'élément d'antenne (12) en coopération avec le bras de
réactance fonctionne en tant que dipôle, le bras de réactance (23, 27, 28, 29) comportant
une longueur de motif qui provoque une résonance à un quart d'une longueur d'onde
unique du signal de communication ou qui provoque une résonance à (λ/4+(n.λ/2)) d'une
longueur d'onde unique du signal de communication, où λ représente une longueur d'onde
et n représente un nombre naturel,
dans lequel le bras de réactance de motif (23) s'étend à partir d'une zone dans laquelle
le circuit sans fil (8) est positionné, le long d'un troisième bord de côté du substrat
(7) qui se trouve à l'opposé du deuxième bord de côté du substrat (7) auquel le faisceau
de câblage (30) est relié au substrat (7), il s'étend le long de ce bord et il continue
à s'étendre le long d'un quatrième bord de côté du substrat (7) qui s'étend parallèlement
à la direction de la première portion droite de la portion façonnée de l'élément d'antenne
(12), laquelle première portion droite commençant à partir de la portion d'extrémité
de l'élément d'antenne (12) qui s'étend dans la direction verticale, dans lequel le
troisième bord de côté et le quatrième bord de côté le long desquels le bras de réactance
de motif (23) est agencé constituent un deuxième coin du substrat (7), dans lequel
le premier coin et le deuxième coin sont diagonalement opposés l'un à l'autre.
2. Dispositif d'antenne (5) selon la revendication 1, dans lequel la première portion
de motif (21) est formée pour avoir une taille égale à un sixième de l'aire totale
du substrat (7).
3. Dispositif d'antenne (5) selon l'une quelconque des revendications précédentes, comprenant
en outre : un convertisseur d'équilibre en déséquilibre (25) agencé entre l'élément
d'antenne (12) et le circuit sans fil (8) et entre le bras de réactance (23) et le
circuit sans fil (8) de sorte qu'un courant déséquilibré ne s'écoule pas vers l'élément
d'antenne (12) et le bras de réactance de motif (23).
4. Dispositif d'antenne (5) selon la revendication 1 ou 2, dans lequel le convertisseur
d'équilibre en déséquilibre (25) comprend un transformateur, le transformateur étant
relié à l'élément d'antenne (12), au bras de réactance (23), et au circuit sans fil
(8), dans lequel le bras de réactance de motif (23) est relié à une masse, de sorte
qu'un courant déséquilibré ne s'écoule pas vers l'élément d'antenne (12) et le bras
de réactance de motif (23).
5. Dispositif d'antenne (5), comprenant :
un substrat en forme de plaque rectangulaire (7) comprenant un câblage de motif avec
une première portion de motif (21) et une deuxième portion de motif (22) qui sont
agencées en isolation positionnelle l'une de l'autre sur le substrat (7), dans lequel
sur la première portion de motif (21) un circuit sans fil (8) et sur la deuxième portion
de motif (22) un circuit électronique (9) sont agencés ;
un élément d'antenne (12) pour transmettre ou recevoir un signal de communication,
dans lequel l'élément d'antenne (12) comprend une portion d'extrémité qui s'étend
dans la direction verticale par rapport à l'extension du substrat à partir d'un point
d'alimentation électrique (11) sur le substrat (7) dans la première portion de motif
(21) et qui est incurvée de 90 degrés, dans lequel à partir de cette portion d'extrémité
incurvée l'élément d'antenne (12) est incurvé deux fois de 90 degrés et s'étend parallèlement
à l'extension du substrat (7) avec une première portion droite, une deuxième portion
droite et une troisième portion droite de sorte que dans cette extension la première
portion droite, la deuxième portion droite et la troisième portion droite constituent
une portion en forme de U de l'élément d'antenne (12), dans lequel la première portion
droite commence à partir de la portion d'extrémité de l'élément d'antenne (12) qui
s'étend dans la direction verticale, dans lequel la première portion droite et la
deuxième portion droite sont agencées le long de deux bords de côté constituant un
premier coin du substrat (7) ;
le circuit sans fil (8) qui est relié à l'élément d'antenne (12) et qui est conçu
pour gérer l'opération de réception du dispositif d'antenne (5) ;
le circuit électronique (9) qui diffère du circuit sans fil (8) et qui est conçu pour
commander l'opération de réception ;
un faisceau de câblage (30) qui sert de conducteur et qui est relié à la deuxième
portion de motif du deuxième bord de côté du substrat (7) pour relier le dispositif
d'antenne (5) à une alimentation électrique ; et
un bras de réactance de motif (23) qui est formé dans la première portion de motif
(21) et qui complète une zone en forme de bande de la première portion de motif (21)
de sorte que la deuxième portion de motif (22) soit empêchée de fonctionner en tant
que plan de masse et l'élément d'antenne (12) en coopération avec le bras de réactance
fonctionne en tant que dipôle,
dans lequel le bras de réactance (27) s'étend à partir d'une zone dans laquelle le
circuit sans fil (8) est positionné le long d'un bord du substrat (7) qui se trouve
à l'opposé d'un bord du substrat (7) auquel le faisceau de câblage (30) est relié
au substrat (7) et s'étend le long de ce bord jusqu'à un deuxième coin, dans lequel
le premier coin et le deuxième coin sont diagonalement opposés l'un à l'autre,
dans lequel un circuit constant regroupé (26) est agencé entre la première portion
de motif (21) et le bras de réactance (27) de sorte que le circuit constant regroupé
(26) fonctionne en faisant partie du bras de réactance de motif (27) et fasse résonner
l'élément d'antenne (12) et le bras de réactance de motif (27) même si le bras de
réactance de motif (27) est plus court qu'un quart d'une longueur d'onde du signal
de communication.
6. Dispositif d'antenne (5) selon la revendication 5, dans lequel le circuit constant
regroupé (26) est un inducteur.